The sudden move sent waves of surprise throughout the Middle East and Saudi Arabia, which has been ruled by autocratic, older men for decades.

During his time as the country's defense minister, Mohammed bin Salman, 31, became known for both shaking up some of the country's officials and picking up his father's conservative, aggressive stances for countries such as Iran, Qatar, and Yemen.

Here's what we know about the life of the Saudi royal who rose to one of the most powerful posts in Saudi Arabia overnight.

Salman has accused Iran of spreading Shia ideology and trying "to control the Islamic world."

"The rise of Mohammed bin Salman will likely mean even more hawkish foreign policy moves from Saudi Arabia and more intensified efforts to confront Iran," said Helima Croft, the global head of commodity strategy at RBC Capital Markets.